Enrolment in the MobiusHD (Vascular Dynamics) CALM (Controlling and lowering blood pressure with the MobiusHD) prospective multicentre safety study for treating resistant hypertension is continuing, following interim data suggesting that the device is safe and effective for lowering blood pressure.

The goal of the developers of the MobiusHD device was to create a carotid implant that would have a durable impact on the carotid baroreceptor to help control blood pressure. The device is a passive implant designed to reshape the carotid sinus, delivered using typical percutaneous techniques and angiographic visualisation. The MobiusHD exerts enough radial force to reshape the sinus in the diastolic phase and prevent migration in the systolic phase with a chronic, rather than acute, impact.

By reshaping the vessel, the MobiusHD increases the differential strain, and therefore the stretch, measured by the baroreceptors with every pulsatile wave concentrated in the windows of the device.

The CALM preliminary safety study is being carried out with 20 US and 30 European patients. Foster presented data from the first 25 patients—six in the USA and 19 in Europe. All patients enrolled had stage 2 resistant hypertension (with office cuff blood pressure of ≥160mmHg) and were on three or more medications (including a diuretic). These included patients that had failed renal sympathetic denervation attempts, both in the USA and Europe. The average age of these patients (11 female and 14 male) was 55 years, the average body mass index score was 30 and the majority (23) were white.

Foster told delegates that 14 of the 25 patients have met the six-month safety endpoint. There were 11 serious adverse events after treatment, seven of which (two vascular access-related events, three hypotensive symptoms and two uncontrolled hypertension) were study-related. All 11 serious adverse events were adequately managed and resolved with no stroke or mortality at six months.

Average blood pressure at baseline was 181/106. By one-year after the procedure, there was on average a 25mmHg drop in systolic blood pressure and a 10mmHg drop in diastolic pressure. The researchers also recorded ambulatory blood pressure reductions of approximately 10–14mmHg systolic and 4–8mmHg diastolic at 180 days post-procedure.

“Our conclusions from this preliminary first-in-man trial are that we should continue and that the preliminary data show that the MobiusHD implant is safe,” said Foster. “In terms of efficacy results, we see a promising signal towards lowering blood pressure in these patients with severe hypertension.”